For a number of reasons (mostly size and the availability of very interesting boutique modules), I have started a small Eurorack system. I am interested in doing some DIY work as well, and quite a few of the Yusynth modules are calling out to be included in the system.

While I have already found this thread about converting the moog filter to 12V:

For dstrength : To answer your question about the odd value of 156K , I first designed the circuit with symetrical values (i.e. 180K) for R5 and R7 but (probably because of the tolerance of some component or some impedance issue I haven't figured out) it was impossible to get the right range for the lowest values, then I simply trimmed the value of R7 until I got the right behaviour. If you have a clue to explain this misbehaviour of the 180K value I buy it._________________YvesLast edited by yusynth on Tue May 31, 2011 3:39 am; edited 2 times in total

Thanks Yves. That makes sense. I simulated the voltage divider section in Multisim in order to see if I could figure out the discrepency. As you'd expect...under simulation you arrive at equal resistor values for the semitone offsets.

I think your explanation is the most logical: an aggregate of tolerance errors...most likely in the trimmers. Perhaps also differences in the absolute value of each voltage rail.

I know this is madness, but I had to squeeze both the 4072 and the Moog Filter into the 4HP Eurorack format:
By the way: It is really easy to achieve a good 1v/oct tracking with the Moog Filter. In self-oscillation you can play beautiful flute-like melodies.
And yes: it's running on +/-12V

Thanks Glitched!
As you can imagine it isn't that easy when the panels are not even 1 inch wide, so I simply solder the pots (9mm Alpha) to perfboard and then fix the PCB on the perfboard.
I haven't got any pix of the filters, but this one here shows what I did to the T. Henry/Fonitronik X-4046 VCO ...
Maybe when I am more confident when it comes to working with aluminum I'll try and make some made-to-measure pot brackets

Thanks so much for sharing that. I always panel-mount my pots when I do a layout on perfboard, but this time I'm getting a "real" pcb from bridechamber.com, which doesn't have spots for pots, on-board.

I don't have the tools to make brackets, so I was a little confused as to what to do! Anyway, yeah, I like your idea of mounting smaller pots on a perfboard, then mounting the PCB to that. I'll probably end up doing something like that. Thanks for the idea!

OK, some update from the 12V/4HP loonie:
Some other YS modules running smoothly at 12V are the ADSR (I actually made an 8HP dual-version) and the Random Module.
Both are easy to build (thanks to Yves' excellent online documentation) and have worked 100% right from the start.
Yves, I cannot bow down often enough to praise your work

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